1. Field of the Invention
This invention lies in the field of crude oil, crude oil transport, and liquid fuels derived from crude oil.
2. Description of the Prior Art
Crude oil is the largest and most widely used source of power in the world. The fuels derived from crude oil enjoy a wide range of utility ranging from consumer uses such as fuels for automotive engines and home heating to commercial and industrial uses such as fuels for boilers, furnaces, smelting units, and power plants. Crude oil is a mixture of hydrocarbons differing widely in molecular weight, boiling and melting points, reactivity, and ease of processing. The mixture includes both light components that are of immediate utility and heavy components that have little or no utility, as well as components such as sulfur that are detrimental to the environment when carried over into the refined products. Many industrial processes have been developed to upgrade crude oil by removing, diluting, or converting the heavier components or those that tend to polymerize or otherwise solidify, notably the olefins, aromatics, and fused-ring compounds such as naphthalenes, indanes and indenes, anthracenes, and phenanthracenes.
Crude oil is found in many parts of the world, including a large number of remote locations. To process the crude, it is therefore often necessary to transport the crude over long distances to processing sites. One of the major modes of transportation is by pipeline, networks of which have been constructed in the United States and Canada as well as other parts of the world. Pipeline transport of crude oil presents certain difficulties, however, prominent among which is the high viscosity of the oil which makes pumping difficult even at mild temperatures, and particularly so in cold climates. The viscosity can be reduced by blending the crude oil with additives such as low-viscosity oils or refinery cuts, but this requires relatively large amounts of these additives and is feasible only where either light-oil fields or a refinery exist at the same site or nearby. The viscosity of heavy oil can also be reduced by heating. To achieve this, however, considerable amounts of heat are required, in addition to large capital expenditures for equipping the pipelines with heating equipment and insulation. A still further method of increasing the mobility of the oil is to add water to the oil to convert it to an emulsion prior to pumping it through the pipeline. Upon reaching its destination, the emulsion is separated into oil and water in a settling tank. To be economically viable, however, the emulsion must be formed with the aid of an emulsifier that produces a readily formed, yet stable, emulsion, and one that functions in the salinities that are often present in crude oil deposits and in the high temperatures often used to extract the oil from the deposits. The emulsifier must also be able to stabilize an emulsion with a high proportion of oil, and yet allow the emulsion to be separated at the destination. Since components of the emulsifier are often retained in the ultimate fuel, the emulsifier must also be one that is not detrimental to the environment when the fuel is burned.
Many crude oil deposits contain natural gas and other gaseous hydrocarbons, commonly referred to as “petroleum gas,” that are released from the deposits together with the crude oil. These gases are released in particularly high amounts when the deposits are injected with water, steam or an inert gas to facilitate the extraction of oil from fields that have already been exhausted with pumps. Unless there is an on-site use for this petroleum gas, it presents a disposal problem. Disposal is commonly achieved by venting the gas to the atmosphere or by combusting the gas in a flare, both of which raise environmental concerns.